Low viscosity poly(alkynyl carbamate) polymers

ABSTRACT

An alternative polyurethane composition is provided which comprises a reaction product of an azidated polyol and a poly(alkynyl carbamate) prepolymer, wherein reaction occurs at a temperature of from 20° C. to 200° C., optionally in the presence of a CuI-containing catalyst and wherein the poly(alkynyl carbamate) prepolymer comprises a reaction product of a polyisocyanate, an alkynol, and a glycol ether, wherein from 1 mol % to 33 mol % of isocyanate groups are reacted with glycol ether and the remaining isocyanate groups are reacted with the alkynol. The inclusion of glycol ethers into the polyisocyanate chain of the poly(alkynyl carbamate) prepolymer at a level of from 1 mol % to 33 mol %, is efficient in reducing the viscosity of the composition without compromising its performance in coatings, adhesives, sealants, films, elastomers, castings, foams, and composites made with the inventive alternative polyurethane compositions.

FIELD OF THE INVENTION

The present invention relates to alternative polyurethane compositionswhich are reaction products of a poly(alkynyl carbamate) prepolymer andan azidated polyol. The azide and alkyne groups react in a 1,3-dipolarcycloaddition to form 1,4- and 1,5-disubstituted triazoles. At least oneof the poly(alkynyl carbamate) and the azidated polyol contain—O(C═O)—NR— functional groups, wherein R=hydrogen or alkyl. Thealternative polyurethane compositions may be thermally cured or may becured with Cu^(I)-containing catalysts and are suitable for use ascoatings, adhesives, sealants, films, elastomers, castings, foams, andcomposites.

BACKGROUND OF THE INVENTION

“Click chemistry” is a term first used by Sharpless et al. (Angew. Chem.Int. Ed. 2001, 40, 2004-2021) to describe a family of syntheticreactions, which attempt to imitate nature by joining small moleculestogether with heteroatom links. Sharpless et al. stated a number ofcriteria that a reaction must meet to be considered a “click” typereaction. These criteria include that the reaction (a) must be modular;(b) must have a wide scope; (c) must provide high yields; (d) mustproduce inoffensive by-products (which can be removed bynon-chromatographic methods); (e) must be stereospecific; and (f) mustinvolve simple reaction conditions (insensitive to water and oxygen) andproduct isolation. Finally, the reaction should use readily availablestarting materials, reactants, and solvents which are easily removed.

One example of a click reaction which has attracted wide attention isthe copper catalyzed azide-alkyne cycloaddition (CuAAC). Thisazide-alkyne cycloaddition was first described by Huisgen in 1963 andwas carried out in the absence of a catalyst, requiring elevatedtemperatures and giving a mixture of products (namely the 1,4 and1,5-substituted triazoles). The Cu^(I)-catalyzed cycloaddition wasdiscovered independently by Meldal (Macromol. Rapid. Com. 2008, 29(12-13), 1016-1051) and Sharpless et al. The benefit seen with thesecopper-catalyzed reactions was that they could be performed at roomtemperature and resulted in the exclusive formation of 1,4-substitutedtriazole products. Another advantage of this cycloaddition is that theazide and alkyne moieties are generally unreactive towards a wide rangeof functional groups, which eliminates the need for extensive use ofprotecting groups. This advantage is a key to the reaction's popularityin a number of scientific fields such as the biomedical field andmaterial science.

Although the initial investigations of 1,3-dipolar cycloadditions viaclick chemistry focused on the functionalization and attachment of smallmolecules to biochemical molecules, U.S. Pat. No. 8,101,238 issued toFokin et al. describes adhesive polymers which are formed frompolyvalent alkynes and azides and can be assembled into cross-linkedpolymer networks by copper catalysis. The Fokin et al. patent describesthe formation of coatings on copper metal surfaces which act as acatalyst for the alkynes and azides to form linear polymers including upto 22 units of a diazide and dialkyne or cross-linked polymericnetworks. The compositions disclosed in Fokin et al. were proposed foruse in applications such as adhesives and coatings and for combinationwith cement and other materials.

Polymeric triazoles constructed by 1,3-dipolar cycloaddition are alsodescribed in U.S. Pat. No. 7,772,358 issued to Tang et al. The compoundsof Tang et al. are prepared by thermal conversion at about 100° C.without the addition of a catalyst, which resulted in the formation ofboth 1,4- and 1,5-disubstituted triazoles. These compositions aredescribed by Tang et al. as being “hyper-branched”, which is a result ofthe exclusive use of tri- or higher substituted alkynes and azidesduring preparation. The advantage of these compositions is that theirpreparation does not involve the use of additional solvents orcatalysts, which might have detrimental effects on the resultingproperties. This benefit, however, is somewhat negated by the need tocure the compositions at elevated temperatures.

Liu, X.-M. et al. in Biomacromolecules 2007, 8, 2653-2658, describe thesynthesis of linear poly(ethylene glycol)s using 1,3-dipolarcycloaddition for chain extension. Liu et al. disclose thatpoly(ethylene glycol)s having pendant alkyne moieties are reacted with2,2-bis(azidomethyl)propane-1,3,diol and copper sulfate/sodiumascorbate.

A significant disadvantage of the above-described reactions is therequired use of di- and polyazides, which have relatively high nitrogencontents. For example, Fokin et al. in U.S. Pat. No. 8,101,238 describecompounds having nitrogen contents of up to about 60% in the form ofazides Such compounds are impracticable for industrial application dueto the compounds' explosiveness. The compounds of Tang et al. andXin-Ming et al. have nitrogen contents in the form of azides of about23% and 43%, respectively, which pose problems when the azide compoundsare handled as such.

Ossipov et al. (Macromolecules 2006, 39, 1709-1718) describe thepreparation of poly(vinyl alcohol)-based hydrogels via 1,3-dipolarcycloaddition, in which a first poly(vinyl alcohol) is functionalizedwith azide functionalities and a second poly(vinyl alcohol) isfunctionalized with alkyne functionalities, and subsequently the twopoly(vinyl alcohol)s are reacted with each other by cyclization of thealkyne and azide groups. Ossipov et al. also disclose that azideterminated poly(ethylene glycol)s may be used as a replacement for theazide-modified poly(vinyl alcohol).

Carter et al. in U.S. Pat. No. 9,790,398 disclose the synthesis of botha diazide monomer and a dialkyne monomer from 4,4′-diphenylmethanediisocyanate (MDI). The inventors also created a diazide monomer byreaction of sodium azide with diglycidyl ether of poly(propylene oxide).Carter et al. disclose the synthesis of only one polymer produced byCuAAC catalyzed reaction of azide-functional poly(propylene glycol)diglycidyl ether with the dialkyne of MDI.

U.S. Pat. Pub. No. 2016/0311973 in the name of Yang et al. is directedto waterborne dispersion coatings that cure by a 1,3-dipolarcycloaddition. Yang et al. disclose hexamethylene diisocyanate(HDI)-based polyurethane/urea dispersions possessing pendent propargylgroups, HDI-based polyurethane/urea dispersions possessing pendent azidegroups, and also alkyd and acrylic type waterborne polymers possessingeither alkyne or azide pendent groups.

Both the Carter et al. and Yang et al. references start from smallmolecules and polymerize these materials to give the final alternativepolyurethane products.

Despite the above-described advancements in technology, the 1,3-dipolarcycloaddition of multivalent azides and alkynes has not been describedin combination with prepolymer precursors to which the azide and alkynegroups have been attached. Such prepolymers would have the advantagethat the azide content of a prepolymer relative to its total weightcould be low enough to minimize the risk of explosions, while the numberof azides in the prepolymer molecules can be higher than two allowingthe formation of cross-linked systems.

To reduce or eliminate problems, therefore, a need continues to exist inthe art for ways of producing alternative polyurethane compositionswhich rely on simple modification of existing prepolymers. Further, itwould be desirable if the alternative polyurethane compositions hadreduced viscosity while maintaining the reactivity and good propertiesof these polymers.

SUMMARY OF THE INVENTION

Accordingly, the present invention reduces or eliminates problemsinherent in the art by providing novel chemical intermediates andmethods of preparation, and polyurethane-based compositions madetherefrom, that cure without the presence of free isocyanates in thefinal curing step.

The present inventors have surprisingly discovered that the introductionof glycol ethers into the polyisocyanate chain of a poly(alkynylcarbamate) prepolymer at a level of from 1 mol % to 33 mol %, isefficient in reducing the viscosity without compromising performance ofalternative polyurethane compositions made from those prepolymers. Thepoly(alkynyl carbamate) prepolymer with reduced viscosity are useful inazido-alkyne cycloaddition (click) chemistry. The coatings, adhesives,sealants, films, elastomers, castings, foams, and composites of thepresent invention may be solvent-borne or waterborne.

These and other advantages and benefits of the present invention will beapparent from the Detailed Description of the Invention herein below.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will now be described for purposes of illustrationand not limitation. Except in the operating examples, or where otherwiseindicated, all numbers expressing quantities, percentages, and so forthin the specification are to be understood as being modified in allinstances by the term “about.”

Any numerical range recited in this specification is intended to includeall sub-ranges of the same numerical precision subsumed within therecited range. For example, a range of “1.0 to 10.0” is intended toinclude all sub-ranges between (and including) the recited minimum valueof 1.0 and the recited maximum value of 10.0, that is, having a minimumvalue equal to or greater than 1.0 and a maximum value equal to or lessthan 10.0, such as, for example, 2.4 to 7.6. Any maximum numericallimitation recited in this specification is intended to include alllower numerical limitations subsumed therein and any minimum numericallimitation recited in this specification is intended to include allhigher numerical limitations subsumed therein. Accordingly, Applicantreserves the right to amend this specification, including the claims, toexpressly recite any sub-range subsumed within the ranges expresslyrecited herein. All such ranges are intended to be inherently describedin this specification such that amending to expressly recite any suchsub-ranges would comply with the requirements of 35 U.S.C. § 112(a), and35 U.S.C. § 132(a). The various embodiments disclosed and described inthis specification can comprise, consist of, or consist essentially ofthe features and characteristics as variously described herein.

Any patent, publication, or other disclosure material identified hereinis incorporated by reference into this specification in its entiretyunless otherwise indicated, but only to the extent that the incorporatedmaterial does not conflict with existing definitions, statements, orother disclosure material expressly set forth in this specification. Assuch, and to the extent necessary, the express disclosure as set forthin this specification supersedes any conflicting material incorporatedby reference herein. Any material, or portion thereof, that is said tobe incorporated by reference into this specification, but whichconflicts with existing definitions, statements, or other disclosurematerial set forth herein, is only incorporated to the extent that noconflict arises between that incorporated material and the existingdisclosure material. Applicant reserves the right to amend thisspecification to expressly recite any subject matter, or portionthereof, incorporated by reference herein.

Reference throughout this specification to “various non-limitingembodiments,” “certain embodiments,” or the like, means that aparticular feature or characteristic may be included in an embodiment.Thus, use of the phrase “in various non-limiting embodiments,” “incertain embodiments,” or the like, in this specification does notnecessarily refer to a common embodiment, and may refer to differentembodiments. Further, the particular features or characteristics may becombined in any suitable manner in one or more embodiments. Thus, theparticular features or characteristics illustrated or described inconnection with various or certain embodiments may be combined, in wholeor in part, with the features or characteristics of one or more otherembodiments without limitation. Such modifications and variations areintended to be included within the scope of the present specification.

The grammatical articles “a”, “an”, and “the”, as used herein, areintended to include “at least one” or “one or more”, unless otherwiseindicated, even if “at least one” or “one or more” is expressly used incertain instances. Thus, these articles are used in this specificationto refer to one or more than one (i.e., to “at least one”) of thegrammatical objects of the article. By way of example, and withoutlimitation, “a component” means one or more components, and thus,possibly, more than one component is contemplated and may be employed orused in an implementation of the described embodiments. Further, the useof a singular noun includes the plural, and the use of a plural nounincludes the singular, unless the context of the usage requiresotherwise.

In a first aspect, the present invention is directed to a poly(alkynylcarbamate) prepolymer comprising a reaction product of a polyisocyanate,an alkynol, and a glycol ether, wherein from 1 mol % to 33 mol % ofisocyanate groups are reacted with the glycol ether and the remainingisocyanate groups are reacted with the alkynol. The present inventorshave unexpectedly found that inclusion of a glycol ether into thepolyisocyanate chain of the poly(alkynyl carbamate) prepolymer at alevel of from 1 mol % to 33 mol %, is efficient in reducing theviscosity of the composition without compromising its performance incoatings, adhesives, sealants, films, elastomers, castings, foams, andcomposites.

In a second aspect, the present invention is directed to an alternativepolyurethane composition comprising a reaction product of an azidatedpolyol and a poly(alkynyl carbamate) prepolymer, wherein reaction occursat a temperature of from 20° C. to 200° C., optionally in the presenceof a Cu^(I)-containing catalyst, and wherein the poly(alkynyl carbamate)prepolymer comprises a reaction product of a polyisocyanate, an alkynol,and a glycol ether, wherein from 1 mol % to 33 mol % of isocyanategroups are reacted with the glycol ether and the remaining isocyanategroups are reacted with the alkynol. The inclusion of a glycol etherinto the polyisocyanate chain of the poly(alkynyl carbamate) prepolymerat a level of from 1 mol % to 33 mol %, is efficient in reducing theviscosity of the composition without compromising its performance incoatings, adhesives, sealants, films, elastomers, castings, foams, andcomposites made with the inventive alternative polyurethanecompositions.

In a third aspect, the present invention is directed to a process ofproducing a poly(alkynyl carbamate) prepolymer, the process comprisingreacting a polyisocyanate, an alkynol, and a glycol ether wherein from 1mol % to 33 mol % of isocyanate groups are reacted with the glycol etherand the remaining isocyanate groups are reacted with the alkynol.

In a fourth aspect, the present invention is directed to a process ofproducing an alternative polyurethane composition, the processcomprising reacting an azidated polyol and a poly(alkynyl carbamate)prepolymer at a temperature of from 20° C. to 200° C. optionally in thepresence of a Cu^(I)-containing catalyst, wherein the poly(alkynylcarbamate) prepolymer comprises a reaction product of a polyisocyanate,an alkynol, and a glycol ether wherein from 1 mol % to 33 mol % ofisocyanate groups are reacted with the glycol ether and the remainingisocyanate groups are reacted with the alkynol.

In a fifth aspect, the present invention provides coatings, adhesives,sealants, films, elastomers, castings, foams, and composites comprisingthe inventive alternative polyurethane composition according to theprevious four paragraphs.

As used herein, the term “polymer” encompasses prepolymers, oligomers,and both homopolymers and copolymers; the prefix “poly” in this contextrefers to two or more. As used herein, the term “molecular weight”, whenused in reference to a polymer, refers to the number average molecularweight, unless otherwise specified.

As used herein, the term “polyol” refers to compounds comprising atleast two free hydroxy groups. Polyols include polymers comprisingpendant and terminal hydroxy groups.

As used herein, the term “coating composition” refers to a mixture ofchemical components that will cure and form a coating when applied to asubstrate.

The terms “adhesive” or “adhesive composition”, refers to any substancethat can adhere or bond two items together. Implicit in the definitionof an “adhesive composition” or “adhesive formulation” is the conceptthat the composition or formulation is a combination or mixture of morethan one species, component or compound, which can include adhesivemonomers, oligomers, and polymers along with other materials.

A “sealant” or “sealant composition” refers to a composition which maybe applied to one or more surfaces to form a protective barrier, forexample to prevent ingress or egress of solid, liquid or gaseousmaterial or alternatively to allow selective permeability through thebarrier to gas and liquid. In particular, it may provide a seal betweensurfaces.

A “film composition” refers to a mixture of chemical components thatwill cure and form a thin flexible strip of material, i.e., a “film”.

An “elastomer” refers to a polymeric composition that has highelongation and flexibility or elasticity. Elastomers may be made fromnatural rubber, polyurethanes, polybutadiene, neoprene, and silicone.

A “casting” or “casting composition” refers to a mixture of liquidchemical components which is usually poured into a mold containing ahollow cavity of the desired shape, and then allowed to solidify.

A “composite” or “composite composition” refers to a material made fromone or more polymers, containing at least one other type of material(e.g., a fiber) which retains its identity while contributing desirableproperties to the composite. A composite has different properties fromthose of the individual polymers/materials which make it up.

A “foam” is produced by mixing a polyol and an isocyanate along with anamine or organometallic catalyst and a combination of water and ahydrofluorocarbon blowing agent.

The terms “cured,” “cured composition” or “cured compound” refer tocomponents and mixtures obtained from reactive curable originalcompound(s) or mixture(s) thereof which have undergone chemical and/orphysical changes such that the original compound(s) or mixture(s)is(are) transformed into a solid, substantially non-flowing material. Atypical curing process may involve crosslinking.

The term “curable” means that an original compound(s) or compositionmaterial(s) can be transformed into a solid, substantially non-flowingmaterial by means of chemical reaction, crosslinking, radiationcrosslinking, or the like. Thus, compositions of the invention arecurable, but unless otherwise specified, the original compound(s) orcomposition material(s) is(are) not cured.

As used herein, the term “solventborne” refers to a composition whichcontains organic solvents rather than water as its primary liquidcomponent.

As used herein, the term “waterborne” refers to a composition,preferably a dispersion, which contains water as its primary liquidcomponent.

The components useful in the present invention comprise apolyisocyanate. As used herein, the term “polyisocyanate” refers tocompounds comprising at least two unreacted isocyanate groups, such asthree or more unreacted isocyanate groups. The polyisocyanate maycomprise diisocyanates such as linear aliphatic polyisocyanates,aromatic polyisocyanates, cycloaliphatic polyisocyanates and aralkylpolyisocyanates.

Suitable polyisocyanates for producing the uretdiones useful inembodiments of the invention include, organic diisocyanates representedby the formula

R(NCO)₂

wherein R represents an organic group obtained by removing theisocyanate groups from an organic diisocyanate having(cyclo)aliphatically bound isocyanate groups and a molecular weight of112 to 1000, preferably 140 to 400. Preferred diisocyanates for theinvention are those represented by the formula wherein R represents adivalent aliphatic hydrocarbon group having from 4 to 18 carbon atoms, adivalent cycloaliphatic hydrocarbon group having from 5 to 15 carbonatoms, or a divalent araliphatic hydrocarbon group having from 7 to 15carbon atoms.

Examples of the organic diisocyanates which are particularly suitablefor the present invention include 1,4-tetramethylene diisocyanate,1,6-hexamethylene diisocyanate, 2,2,4-trimethyl-1,6-hexamethylenediisocyanate, 1,12-dodecamethylene diisocyanate, cyclohexane-1,3- and1,4-diisocyanate, 1-isocyanato-2-isocyanato-methyl cyclopentane,1-isocyanato-3-isocyanatomethyl-3,5,5-trimethyl cyclohexane (isophoronediisocyanate or IPDI), bis-(4-isocyanatocyclohexyl)methane, 1,3- and1,4-bis(isocyanatomethyl)-cyclohexane,bis-(4-isocyanato-3-methyl-cyclohexyl)-methane,α,α,α′,α′-tetramethyl-1,3- and 1,4-xylene diisocyanate,1-isocyanato-1-methyl-4(3)-isocyanato-methyl cyclohexane, and 2,4- and2,6-hexahydrotoluene diisocyanate, toluene diisocyanate (TDI),diphenylmethane diisocyanate (MDI), pentane diisocyanate(PDI)—bio-based), and, isomers of any of these; or combinations of anyof these. Mixtures of diisocyanates may also be used. Preferreddiisocyanates include 1,6-hexamethylene diisocyanate, isophoronediisocyanate, and bis(4-isocyanatocyclohexyl)-methane because they arereadily available and yield relatively low viscosity oligomers.

Polyisocyanate adducts containing isocyanurate, iminooxadiazine dione,urethane, biuret, allophanate, uretdione and/or carbodiimide groups arealso suitable for use in the present invention, and may be prepared fromthe same organic groups, R, described above. Such polyisocyanates mayhave isocyanate functionalities of 3 or more and can be prepared, forexample, by the trimerization or oligomerization of diisocyanates or bythe reaction of diisocyanates with polyfunctional compounds containinghydroxyl or amine groups. In certain embodiments, the polyisocyanate isthe isocyanurate of hexamethylene diisocyanate, which may be prepared inaccordance with U.S. Pat. No. 4,324,879 at col. 3, line 5 to col. 6,line 47.

The polyols useful in the present invention may be either low molecularweight (62-399 Da, as determined by gel permeation chromatography) orhigh molecular weight (400 to 10,000 Da, as determined by gel permeationchromatography) materials and in various embodiments will have averagehydroxyl values as determined by ASTM E222-17, Method B, of between 1000and 10, and preferably between 500 and 50.

The polyols in the present invention include low molecular weight diols,triols and higher alcohols and polymeric polyols such as polyesterpolyols, polyether polyols, polycarbonate polyols, polyurethane polyolsand hydroxy-containing (meth)acrylic polymers.

The low molecular weight diols, triols, and higher alcohols useful inthe present invention are known to those skilled in the art. In manyembodiments, they are monomeric and have hydroxyl values of 200 andabove, usually within the range of 1500 to 200. Such materials includealiphatic polyols, particularly alkylene polyols containing from 2 to 18carbon atoms. Examples include ethylene glycol, 1,4-butanediol,1,6-hexanediol, and cycloaliphatic polyols such as cyclohexanedimethanol. Examples of triols and higher alcohols include trimethylolpropane and pentaerythritol. Also useful are polyols containing etherlinkages such as diethylene glycol and triethylene glycol.

In various embodiments, the suitable polyols are polymeric polyolshaving hydroxyl values less than 200, such as 10 to 180. Examples ofpolymeric polyols include polyalkylene ether polyols, polyester polyolsincluding hydroxyl-containing polycaprolactones, hydroxy-containing(meth)acrylic polymers, polycarbonate polyols and polyurethane polymers.

Examples of polyether polyols include poly(oxytetramethylene) glycols,poly(oxyethylene) glycols, and the reaction product of ethylene glycolwith a mixture of propylene oxide and ethylene oxide.

Also useful are polyether polyols formed from the oxyalkylation ofvarious polyols, for example, glycols such as ethylene glycol,1,4-butane glycol, 1,6-hexanediol, and the like, or higher polyols, suchas trimethylol propane, pentaerythritol and the like. One commonlyutilized oxyalkylation method is reaction of a polyol with an alkyleneoxide, for example, ethylene oxide in the presence of an acidic or basiccatalyst.

Polyester polyols can also be used as a polymeric polyol component inthe certain embodiments of the invention. The polyester polyols can beprepared by the polyesterification of organic polycarboxylic acids oranhydrides thereof with organic polyols. Preferably, the polycarboxylicacids and polyols are aliphatic or aromatic dibasic acids and diols.

The diols which may be employed in making the polyester include alkyleneglycols, such as ethylene glycol and butylene glycol, neopentyl glycoland other glycols such as cyclohexane dimethanol, caprolactone diol (forexample, the reaction product of caprolactone and ethylene glycol),polyether glycols, for example, poly(oxytetramethylene) glycol and thelike. However, other diols of various types and, as indicated, polyolsof higher functionality may also be utilized in various embodiments ofthe invention. Such higher polyols can include, for example, trimethylolpropane, trimethylol ethane, pentaerythritol, and the like, as well ashigher molecular weight polyols such as those produced by oxyalkylatinglow molecular weight polyols. An example of such high molecular weightpolyol is the reaction product of 20 moles of ethylene oxide per mole oftrimethylol propane.

The acid component of the polyester consists primarily of monomericcarboxylic acids or anhydrides having 2 to 18 carbon atoms per molecule.Among the acids which are useful are phthalic acid, isophthalic acid,terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid,adipic acid, azelaic acid, sebacic acid, maleic acid, glutaric acid,chlorendic acid, tetrachlorophthalic acid and other dicarboxylic acidsof varying types. Also, there may be employed higher polycarboxylicacids such as trimellitic acid and tricarballylic acid (where acids arereferred to above, it is understood that the anhydrides of those acidswhich form anhydrides can be used in place of the acid). Also, loweralkyl esters of acids such as dimethyl glutamate can be used.

In addition to polyester polyols formed from polybasic acids andpolyols, polycaprolactone-type polyesters can also be employed. Theseproducts are formed from the reaction of a cyclic lactone such asc-caprolactone with a polyol with primary hydroxyls such as thosementioned above. Such products are described in U.S. Pat. No. 3,169,949.

In addition to the polyether and polyester polyols, hydroxy-containing(meth)acrylic polymers or (meth)acrylic polyols can be used as thepolyol component.

Among the (meth)acrylic polymers are polymers of 2 to 20 percent byweight primary hydroxy-containing vinyl monomers such as hydroxyalkylacrylate and methacrylate having 2 to 6 carbon atoms in the alkyl groupand 80 to 98 percent by weight of other ethylenically unsaturatedcopolymerizable materials such as alkyl(meth)acrylates; the percentagesby weight being based on the total weight of the monomeric charge.

Examples of suitable hydroxy alkyl(meth)acrylates are hydroxy ethyl andhydroxy butyl(meth)acrylate. Examples of suitable alkyl acrylates and(meth)acrylates are lauryl methacrylate, 2-ethylhexyl methacrylate andn-butyl acrylate.

In addition to the acrylates and methacrylates, other copolymerizablemonomers which can be copolymerized with the hydroxyalkyl(meth)acrylates include ethylenically unsaturated materials such asmonoolefinic and diolefinic hydrocarbons, halogenated monoolefinic anddiolefinic hydrocarbons, unsaturated esters of organic and inorganicacids, amides and esters of unsaturated acids, nitriles and unsaturatedacids and the like. Examples of such monomers include styrene,1,3-butadiene, acrylamide, acrylonitrile, α-methyl styrene, α-methylchlorostyrene, vinyl butyrate, vinyl acetate, alkyl chloride, divinylbenzene, diallyl itaconate, triallyl cyanurate and mixtures thereof.Preferably, these other ethylenically unsaturated materials are used inadmixture with the above-mentioned acrylates and methacrylates.

In certain embodiments of the invention, the polyol may be apolyurethane polyol. These polyols can be prepared by reacting any ofthe above-mentioned polyols with a minor amount of polyisocyanate(OH/NCO equivalent ratio greater than 1:1) so that free primary hydroxylgroups are present in the product. In addition to the high molecularweight polyols mentioned above, mixtures of both high molecular weightand low molecular weight polyols such as those mentioned above may beused.

Suitable hydroxy-functional polycarbonate polyols may be those preparedby reacting monomeric diols (such as 1,4-butanediol, 1,6-hexanediol,di-, tri- or tetraethylene glycol, di-, tri- or tetrapropylene glycol,3-methyl-1,5-pentanediol, 4,4′-dimethylolcyclohexane and mixturesthereof) with diaryl carbonates (such as diphenyl carbonate, dialkylcarbonates (such as dimethyl carbonate and diethyl carbonate), alkylenecarbonates (such as ethylene carbonate or propylene carbonate), orphosgene. Optionally, a minor amount of higher functional, monomericpolyols, such as trimethylolpropane, glycerol or pentaerythritol, may beused.

In various embodiments, the azidated polyols are the reaction productsof a polyol and methane sulfonyl chloride (or toluenesulfonyl (tosyl),p-bromophenylsulfonyl (brosyl), benzyl) in presence of base, followed bydisplacement of the methanesulfonate by an azide anion using NaN₃.Another method to produce azidated polyols is the reaction of apolyoxirane compound, for example, a (meth)acrylic polymer containingglycidyl methacrylate comonomer units, with an azide ion using, forexample, NaN₃. Any polyol, including but not limited to, those disclosedherein may be azidated and useful in the invention.

The azidated polyol useful in the present application may have anitrogen content derivable from azide relative to the total weight ofthe molecule in various embodiment of 20 wt.-% or less, in certainembodiments of 18 wt.-% or less, or of 16 wt.-% or less and in selectedembodiments of 15 wt.-% or less. Having such a low azide content helpsto ensure that the polyols are sufficiently stable against explosivedecomposition, such that extensive handling precautions can be avoided.On the other hand, it is preferred that the nitrogen content derivablefrom azide relative to the total weight of the molecule in the azidepolyol in various embodiments is 1 wt.-% or more, in some embodiments, 2wt.-% or more, in certain embodiments, 5 wt.-% or more and in selectedembodiments, 8 wt.-% or more. Such an azide content ensures that thepolyols have a sufficiently low viscosity during handling, but alsopermits the azidated polyol to contain multiple azide groups.

In various embodiments, the alkyne-containing alkylation agent is apropargyl halogenide, in certain embodiments, a propargyl chloride orbromide, as such compounds are readily available and relativelyinexpensive.

In selected embodiments, the alkyne is obtainable by the reaction of apolyisocyanate or isocyanate-terminated polyurethane prepolymer and analkyne having a functional group reactive towards isocyanates. Thefunctional group reactive towards isocyanates may be an amine, hydroxylor thiol group. The alkyne may be straight chain or branched and containcyclic moieties. In various embodiments, the alkyne contains from 3 to10 carbon atoms; in other embodiments from 3 to 8 carbon atoms. Apreferred alkyne for the reaction with polyisocyanates or polyisocyanateprepolymer is propargyl alcohol.

In various embodiments, the alkyne-containing alkylation agent is analkynol, in certain embodiments, a propiolate, in certain embodiments,2-hydroxyethylpropiolate (2-HEP).

In selected embodiments, the alkyne is obtained by the reaction of apolyisocyanate or isocyanate-terminated polyurethane prepolymer and analkyne having a functional group reactive towards isocyanates. Thefunctional group reactive towards isocyanates may be an amine, hydroxylor thiol group. The alkyne may be straight chain or branched and containcyclic moieties. In various embodiments, the alkyne contains from 3 to10 carbon atoms; in other embodiments from 3 to 8 carbon atoms.

The alternative polyurethane compositions of the present invention areobtained by reacting an azide compound having two or more azide groupsattached thereto and an alkyne compound having two or more alkyne groupsattached thereto in a 1,3-dipolar cycloaddition of the azide and alkynegroups. This can for example, be achieved by heating the components totemperatures sufficient to affect the cycloaddition such as in variousembodiments, at least 100° C., in certain embodiments, at least 200° C.and in selected embodiments, at least 210° C.

In certain embodiments, the optional catalyst in the present inventionmay be a Cu^(I)-based catalyst. The Cu^(I)-based catalyst may, forexample, be a copper-containing surface which contains sufficient Cu^(I)in the surface layer to provide the required catalytic action. Ifapplication of the inventive composition to non copper-containingsurfaces is intended, it is necessary that the Cu^(I)-based catalystcome from a copper source which is not attached to the surface of amaterial to which the alternative polyurethane composition is to beapplied.

Suitable copper catalysts of this type can be based on commerciallyavailable Cu^(I) salts such as CuBr or CuI. It has been noted thatCu^(I) precursors do not provide catalysts with high reactivities in theformation of 1,4-disubstituted triazoles when azide compounds having twoor more azide groups attached thereto and alkyne compounds having two ormore alkyne groups attached to a molecule are reacted; however, Cu^(II)precursors which are converted to Cu^(I) by the action of a reducingagent, provide enhanced activity. Suitable Cu^(II) precursors include,but are not limited to, copper(II) sulfate, copper(II) acetatemonohydrate, and copper(II) 2-ethylhexanoate. Suitable reducing agentsinclude for example triphenyl phosphine, sodium ascorbate, tin(II)2-ethylhexanoate, and hydroquinone.

In various embodiments, suitable glycol ethers include, but are notlimited to, ethylene glycol monomethyl ether, ethylene glycol monoethylether, ethylene glycol monopropyl ether, ethylene glycol monoisopropylether, ethylene glycol monobutyl ether, ethylene glycol monophenylether, ethylene glycol monobenzyl ether, propylene glycol methyl ether,diethylene glycol monomethyl ether, diethylene glycol monoethyl ether,diethylene glycol mono-n-butyl ether, and dipropyleneglycol methylether. In certain embodiments, the glycol ether is one of ethyleneglycol monoethyl ether (EGMEE), diethylene glycol monoethyl ether(DEGMEE), and diethylene glycol monobutyl ether (DEGBE).

In various embodiments, the alternative polyurethane compositions of thepresent invention may be used to provide coatings, adhesives, sealants,films, elastomers, castings, foams, and composites.

The alternative polyurethane compositions of the present invention mayfurther include any of a variety of additives such as defoamers,devolatilizers, surfactants, thickeners, flow control additives,colorants (including pigments and dyes) or surface additives.

The alternative polyurethane compositions of the invention may becontacted with a substrate by any methods known to those skilled in theart, including but not limited to, spraying, dipping, flow coating,rolling, brushing, pouring, and the like. In some embodiments, theinventive compositions may be applied in the form of paints or lacquersonto any compatible substrate, such as, for example, metals, plastics,ceramics, glass, and natural materials. In certain embodiments, theinventive composition is applied as a single layer. In otherembodiments, the composition of the present invention may be applied asmultiple layers as needed.

EXAMPLES

The non-limiting and non-exhaustive examples that follow are intended tofurther describe various non-limiting and non-exhaustive embodimentswithout restricting the scope of the embodiments described in thisspecification. All quantities given in “percents” are understood to beby weight, unless otherwise indicated. For POLY(ALKYNYL CARBAMATE)PREPOLYMERS B, C, D, E, F, G, H, I, and J, described herein, it will beunderstood that modification with a given mole percentage of a glycolether, for example 10 mol %, will mean that the resulting poly(alkynylcarbamate) consisted of 100% carbamate functionality, i.e., allisocyanate groups were reacted, and that 10 mol % of those carbamatefunctionalities were formed by reaction with the glycol ether and 90 mol% of those carbamate functionalities were formed by reaction withALKYLNOL A. Similarly, 25 mol % modification will be understood to meanthat 25 mol % of those carbamate functions were formed by reaction withthe glycol ether and 75 mol % of those carbamate functionalities wereformed by reaction with ALKYLNOL A, and so on. For the purpose of massto mole conversions, reagents with purity of 99% or higher areconsidered to be 100% pure.

Although described herein in the context of a coating, those skilled inthe art will recognize that the principles of the present invention areequally applicable to adhesives, sealants, films, elastomers, castings,foams, and composites.

The following materials were used in preparation of the Examples:

-   POLYISOCYANATE A an allophanate-modified polyisocyanate having    isocyanate equivalent weight of 217.72 g/eq, commercially available    from Covestro LLC (Pittsburgh, Pa.) as DESMODUR XP 2580 (19.3%    isocyanate);-   POLYOL A an acrylic polyol, received as a 80% solids solution in    n-BA, commercially available from Allnex as SETALUX DA 870 BA,    possessing hydroxyl equivalent weight of 461.02 g/eq (at 100%    solids);-   GLYCOL ETHER A ethylene glycol monoethyl ether (EGMEE), laboratory    grade, commercially available from Fisher Scientific;-   GLYCOL ETHER B diethylene glycol monoethyl ether (DEGMEE),    REAGENTPLUS, 99%, commercially available from Sigma-Aldrich;-   GLYCOL ETHER C diethylene glycol monobutyl ether (DEGBE) (≥99%),    commercially available from Sigma-Aldrich);-   POLY(ALKYNYL a proprietary prepolymer based on CARBAMATE)    POLYISOCYANATE A, having an alkyne equivalent PREPOLYMER A weight of    273.78 g/eq;-   POLY(ALKYNYL a proprietary prepolymer based on CARBAMATE)    POLYISOCYANATE A modified with 10 mol % PREPOLYMER B GLYCOL ETHER A,    having alkyne equivalent weight of 307.99 g/eq;-   POLY(ALKYNYL a proprietary prepolymer based on CARBAMATE)    POLYISOCYANATE A modified with 25 mol % PREPOLYMER C GLYCOL ETHER A,    having alkyne equivalent weight of 376.40 g/eq;-   POLY(ALKYNYL a proprietary prepolymer based on CARBAMATE)    POLYISOCYANATE A modified with 33 mol % PREPOLYMER D GLYCOL ETHER A,    having alkyne equivalent weight of 425.40 g/eq;-   POLY(ALKYNYL a proprietary prepolymer based on CARBAMATE)    POLYISOCYANATE A modified with 10 mol % PREPOLYMER E GLYCOL ETHER B,    having alkyne equivalent weight of 312.88 g/eq;-   POLY(ALKYNYL a proprietary prepolymer based on CARBAMATE)    POLYISOCYANATE A modified with 25 mol % PREPOLYMER F GLYCOL ETHER B,    having alkyne equivalent weight of 391.08 g/eq;-   POLY(ALKYNYL a proprietary prepolymer based on CARBAMATE)    POLYISOCYANATE A modified with 33 mol % PREPOLYMER G GLYCOL ETHER B,    having alkyne equivalent weight of 447.10 g/eq;-   POLY(ALKYNYL a proprietary prepolymer based on CARBAMATE)    POLYISOCYANATE A modified with 10 mol % PREPOLYMER H GLYCOL ETHER C,    having alkyne equivalent weight of 316.00 g/eq;-   POLY(ALKYNYL a proprietary prepolymer based on CARBAMATE)    POLYISOCYANATE A modified with 25 mol % PREPOLYMER I GLYCOL ETHER C,    having alkyne equivalent weight of 400.43 g/eq;-   POLY(ALKYNYL a proprietary prepolymer based on CARBAMATE)    POLYISOCYANATE A modified with 33 mol % PREPOLYMER J GLYCOL ETHER C,    having alkyne equivalent weight of 460.92 g/eq;-   AZIDATED POLYOL A a proprietary prepolymer based on POLYOL A, having    azide equivalent weight of 532.74 g/eq (at 91.23% solids); the    solid% was determined by drying an aliquot in an oven and recording    the fraction weight remaining;-   4 Å Molecular Sieves Fisher Scientific, Type 4A, Grade 514, 8-12    Mesh beads, 4 Å pore size, activated using microwave oven prior to    use;-   ALKYNOL A propargyl alcohol (99%), commercially available from    Fisher Scientific; reagent was dried over 4 Å molecular sieves prior    to use;-   ALKYNOL B 2-hydroxyethylpropiolate;-   TEA triethylamine (≥99.5%), commercially available from    Sigma-Aldrich; reagent was dried over 4 Å molecular sieves prior to    use;-   MeCN acetonitrile (OPTIMA), commercially available from Fisher    Scientific; solvent was distilled and dried over 4 Å molecular    sieves prior to use;-   Mesyl-Cl methanesulfonyl chloride (≥99.7%), commercially available    from Sigma-Aldrich;-   PMDETA N,N,N′,N″,N″-pentamethyldiethylenetriamine ligand (99%),    commercially available from Sigma-Aldrich;-   DCM dichloromethane (Certified ACS), commercially available from    Fisher Scientific;-   DMF N,N-dimethylformamide (Certified ACS), commercially available    from Fisher Scientific;-   NaN₃ sodium azide (REAGENTPLUS, ≥99.5%), commercially available from    Sigma-Aldrich;-   n-BA n-butyl acetate, ACS reagent, ≥99.5%, commercially available    from Sigma-Aldrich; solvent was dried over 4 Å molecular sieves    prior to use;-   MEK methyl ethyl ketone, Certified ACS, commercially available from    Sigma-Aldrich;-   Ethyl acetate ethyl acetate (Certified ACS), commercially available    from Fisher Scientific;-   CATALYST A dibutyltin dilaurate (DBTDL 98%), commercially available    from Strem Chemicals;-   CATALYST B a proprietary CuCl₂[PMDETA] catalyst complex;-   Brine saturated aqueous solution of NaCl, prepared by dissolving 450    g NaCl (certified ACS, Fisher Scientific) into 1.2 L of DI water at    room temperature;-   MgSO₄ magnesium sulfate, anhydrous, commercially available from    Fisher Scientific; and,-   CuCl₂ copper(II) chloride, 97%, commercially available from    Sigma-Aldrich.

Synthesis of POLY(ALKYNYL CARBAMATE) PREPOLYMER A

All glassware was cleaned and dried in an oven overnight. The followingprocedure was performed in a N₂-protected, dry box equipped with acryostated heptane bath. POLYISOCYANATE A (101.02 g, 0.464 molisocyanate) and CATALYST A (1.09 g, 1.73 mmol) were charged to a 500 mLthree-neck round bottom flask equipped with a mechanical stirrer, athermocouple, and an addition funnel. The mixture in the flask wasstirred and allowed to equilibrate at 0° C. for ten minutes. Afterequilibration, ALKYNOL A (26.102 g, 0.466 mol) was charged to theaddition funnel and then added into the stirring solution at initially 1drop/sec. The addition speed was adjusted so that temperature of thereaction would not exceed 30° C. After the addition was complete, themixture was allowed to react overnight, and the product of the reactionwas characterized by FTIR, ¹³C-NMR and ¹H-NMR.

Synthesis of POLY(ALKYNYL CARBAMATE) PREPOLYMER B

All glassware was cleaned and dried in an oven overnight. The followingprocedure was performed in a N₂-protected dry box equipped with acryostated heptane bath. POLYISOCYANATE A (75.137 g, 0.345 molisocyanate) and CATALYST A (0.752 g) were charged to a three-neck, 250mL round bottom flask equipped with a mechanical stirrer, athermocouple, and an addition funnel. GLYCOL ETHER A (3.109 g, 0.035mol) was added to the addition funnel. The mixture in the flask wasstirred and allowed to equilibrate at 0° C. for ten minutes. After theequilibration, GLYCOL ETHER A was added into the stirring solution atinitially 1 drop/sec. The addition speed was adjusted so thattemperature of the reaction did not exceed 30° C. At this point, ALKYNOLA (17.389 g, 0.310 mol) was added to the top of the addition funnelusing a syringe. The same temperature precautions were taken during theaddition of ALKYNOL A as were taken during the addition of GLYCOL ETHERA. After the addition, the mixture was allowed to react overnight. Theproduct of the reaction was characterized by ¹³C-NMR and ¹H-NMR.

Synthesis of POLY(ALKYNYL CARBAMATE) PREPOLYMERS C, D, E, F, G, H, I,and J

POLY(ALKYNYL CARBAMATE) PREPOLYMER C was made following the sameprocedure as POLY(ALKYNYL CARBAMATE) PREPOLYMER B: POLYISOCYANATE A(75.134 g, 0.345 mol isocyanate), CATALYST A (0.751 g), GLYCOL ETHER A(7.774 g, 0.086 mol), and ALKYNOL A (14.492 g, 0.259 mol) were used.

POLY(ALKYNYL CARBAMATE) PREPOLYMER D was made following the sameprocedure as POLY(ALKYNYL CARBAMATE) PREPOLYMER B: POLYISOCYANATE A(75.121 g, 0.345 mol isocyanate), CATALYST A (0.750 g), GLYCOL ETHER A(10.274 g, 0.114 mol), and ALKYNOL A (13.047 g, 0.233 mol) were used.

POLY(ALKYNYL CARBAMATE) PREPOLYMER E was made following the sameprocedure as POLY(ALKYNYL CARBAMATE) PREPOLYMER B, except GLYCOL ETHER Bwas used instead of GLYCOL ETHER A: POLYISOCYANATE A (75.141 g, 0.345mol isocyanate), CATALYST A (0.751 g), GLYCOL ETHER B (4.696 g 0.035mol), and ALKYNOL A (17.361 g, 0.310 mol) were used.

POLY(ALKYNYL CARBAMATE) PREPOLYMER F was made following the sameprocedure as POLY(ALKYNYL CARBAMATE) PREPOLYMER E: POLYISOCYANATE A(75.152 g, 0.345 mol isocyanate), CATALYST A (0.753 g), GLYCOL ETHER B(11.539 g, 0.086 mol), and ALKYNOL A (14.504 g, 0.259 mol) were used.

POLY(ALKYNYL CARBAMATE) PREPOLYMER G was made following the sameprocedure as POLY(ALKYNYL CARBAMATE) PREPOLYMER E: POLYISOCYANATE A(75.126 g, 0.345 mol isocyanate), CATALYST A (0.751 g), GLYCOL ETHER B(15.312 g, 0.114 mol), and ALKYNOL A (12.941 g, 0.231 mol) were used.

POLY(ALKYNYL CARBAMATE) PREPOLYMER H was made following the sameprocedure as POLY(ALKYNYL CARBAMATE) PREPOLYMER B, except GLYCOL ETHER Cwas used instead of GLYCOL ETHER A: POLYISOCYANATE A (75.127 g, 0.345mol isocyanate), CATALYST A (0.751 g), GLYCOL ETHER C (5.678 g, 0.035mol), and ALKYNOL A (17.373 g, 0.310 mol) were used.

POLY(ALKYNYL CARBAMATE) PREPOLYMER I was made following the sameprocedure as POLY(ALKYNYL CARBAMATE) PREPOLYMER H: POLYISOCYANATE A(75.129 g, 0.345 mol isocyanate), CATALYST A (0.751 g), GLYCOL ETHER C(13.951 g, 0.086 mol), and ALKYNOL A (14.509 g, 0.259 mol) were used.

POLY(ALKYNYL CARBAMATE) PREPOLYMER J was made following the sameprocedure as POLY(ALKYNYL CARBAMATE) PREPOLYMER H: POLYISOCYANATE A(75.134 g, 0.345 mol isocyanate), CATALYST A (0.750 g), GLYCOL ETHER C(18.494 g, 0.114 mol), and ALKYNOL A (13.014 g, 0.232 mol) was used.

Synthesis of AZIDATED POLYOL A

All glassware was cleaned and dried in an oven overnight. The followingprocedure was performed in a N₂-protected dry box equipped with acryostated heptane bath. POLYOL A (151.2 g, 0.262 mol), TEA (55.0 mL,0.395 mol) and MeCN (300 mL) were charged to a one-liter, two-neck roundbottom flask equipped with a mechanical stirrer and an addition funnel.The mixture was stirred and allowed to equilibrate at 0° C. for tenminutes. After equilibration, a solution of mesyl-Cl (24.0 mL, 0.310mol) in MeCN (50 mL) was charged to the addition funnel and added intothe stirring solution at 1 drop/sec. After the addition, the mixture wasallowed to react overnight.

The reaction flask was transferred out of the dry box, and the mixturewas filtered to remove the TEA salts. MeCN and excess TEA were vacuumstripped, and the mesylated resin was re-dissolved into ethyl acetate(500 mL). The solution was washed with 20/80 (v/v) brine/DI watermixture (3×300 mL) and then brine (300 mL) and dried with MgSO₄overnight. Ethyl acetate was removed by vacuum stripping to afford themesylated POLYOL A as an intermediate. An aliquot was taken to performFTIR, ¹³C-NMR and ¹H-NMR characterization.

The mesylated resin was re-dissolved in MeCN (300 mL) and DMF (30 mL) ina one liter, one-neck round bottom flask. NaN₃ (20.0 g, 0.308 mol) and astir bar were added to the mixture, and the flask was equipped with acondenser sealed with a rubber septum with a needle. The mixture wasstirred at 95° C. for 16 hours, allowed to cool to room temperature, andfiltered to remove the Na mesylate salts. MeCN was vacuum stripped, andthe azidated resin was re-dissolved into 500 mL ethyl acetate. Thesolution was washed with 20/80 (v/v), brine/water mixture (3×300 mL) andthen brine (3×300 mL) and dried with MgSO₄ overnight. The final product,AZIDATED POLYOL A, was isolated by removal of ethyl acetate by vacuumstripping and thereafter characterized by FTIR, ¹³C-NMR, and ¹H-NMR. Analiquot of the product was placed on an aluminum pan and dried in theoven at 100° C. for one hour.

Synthesis of CATALYST B

CuCl₂ (0.993 g; 7.39 mmol) and MeCN (7.5 mL) were charged to a 100 mLsingle neck round-bottom flask. PMDETA (1.283 g; 7.40 mmol) was addeddropwise to the stirred solution. Upon the addition, the reactionmixture turned from a brown color to turquoise. After reacting at roomtemperature for 24 hours, the MeCN was removed in vacuo to yield thefinal product as a blue powder.

Fourier transform infrared spectroscopy (FTIR) studies were conductedusing a NICOLET 8700 spectrometer with a KBr beam splitter and a DTGSdetector. Samples were sandwiched between two NaCl salt plates (polishedwith DCM) of approximate thickness of 5 mm.

Proton nuclear magnetic resonance (¹H NMR) spectra and carbon nuclearmagnetic resonance (¹³C NMR) spectra were obtained using a 600.13 MHzVarian Mercury^(plus) NMR (VNMR 6.1C) spectrometer. For ¹H NMR, typicalacquisition parameters were 8 s recycle delay, 7.8 μs pulsecorresponding to a 45° flip angle, and an acquisition time of 1.998 s.The number of scans acquired for each sample was 64. All ¹H chemicalshifts were referenced to tetramethylsilane (TMS) (0 ppm). Samplesolutions were prepared at a concentration of approximately 5-10% indeuterated chloroform (CDCl₃) (99.8+ atom % D, 0.03 v/v % TMS) (AcrosOrganics, further dried using activated molecular sieves prior to use),and the resulting solution was charged to a 5 mm NMR tube. For ¹³C NMR,typical acquisition parameters were 1 sec recycle delay, 11 ms pulsecorresponding to a 45° flip angle, and an acquisition time of 0.908 s.The number of scans acquired for each sample was 1024. All ¹³C chemicalshifts were referenced to residual chloroform (77.16 ppm). Samplesolutions were prepared at a concentration of approximately 30% inCDCl₃, and the resulting solution was charged to a 5 mm NMR tube.

Differential scanning calorimetry (DSC) was performed using a TAInstruments Q200. For this purpose, coatings were prepared onpolyethylene (PE) film substrate. The coatings, which had littleadhesion to the PE film, were easily peeled off and punched to givecircular samples (d=0.25 in) of the coating films. Stacks of five suchsamples (total ˜5 mg) per coating were placed in a hermetically sealedT_(zero) pan. A heat/cool/heat cycle was performed on each stackstarting at −50° C. and ending at 200° C. at a rate of 10° C./min. Theglass transition temperature (T_(g)) of the cured material wasdetermined from the second heating cycle, and TA Universal Analysissoftware was used to determine the midpoint of the T_(g) inflection asthe reported value.

Isothermal viscosity was measured using a strain-controlled ARESrheometer (TA Instruments) at room temperature using cone and platemethodology. The cone had a diameter of 50.0 mm with an angle of 0.04radians, and the gap applied between the cone and the plate during testswas 0.053 mm. The frequency used was 1 rad/s. Strain sweeps wereperformed on all specimens. The results showed that 50% strain fellwithin the linear viscoelastic regime for nearly all specimens, andtherefore this strain value was used for all subsequent viscositymeasurements. For each sample, data were collected in 10 s intervalsover a 30-minute period resulting in 180 total data points; the reportedviscosity of the sample was calculated as the average of these 180 datapoints. The results are provided in Table I.

By reference to Table I, POLY(ALKYNYL CARBAMATE) PREPOLYMER A was analkyne-functional control polyurethane that was unmodified with glycolether. POLY(ALKYNYL CARBAMATE) PREPOLYMERS B, C, and D were modifiedwith 10, 25, and 33 mol % GLYCOL ETHER A, respectively. POLY(ALKYNYLCARBAMATE) PREPOLYMERS E, F, and G were modified with 10, 25, and 33 mol% GLYCOL ETHER B, respectively. POLY(ALKYNYL CARBAMATE) PREPOLYMERS H,I, and J were modified with 10, 25, and 33 mol % GLYCOL ETHER C,respectively.

The POLY(ALKYNYL CARBAMATE) prepolymers in Table I were modified todetermine the viscosity response of the resins from the addition of ashort chain mono alcohol. In the case of GLYCOL ETHER A, 10 mol %modification increased the viscosity; however, 25 and 33 mol % reducedthe viscosity of POLY(ALKYNYL CARBAMATE) PREPOLYMERS when compared tounmodified POLY(ALKYNYL CARBAMATE) PREPOLYMER A. Likewise, in the caseof GLYCOL ETHER B, 10 mol % modification increased the viscosity;however, 25 and 33 mol % reduced the viscosity of POLY(ALKYNYLCARBAMATE) PREPOLYMERS when compared to unmodified POLY(ALKYNYLCARBAMATE) PREPOLYMER A. In the case of GLYCOL ETHER C, allmodifications (10, 25, and 33 mol %) reduced the viscosity ofPOLY(ALKYNYL CARBAMATE) PREPOLYMERS when compared to unmodifiedPOLY(ALKYNYL CARBAMATE) PREPOLYMER A.

TABLE I Modification POLY(ALKYNYL CARBAMATE) Glycol Amount ViscosityPREPOLYMER Ether (mol %) (mPa-s) A None — 79,623 B A 10 127,590 C A 2565,242 D A 33 75,614 E B 10 80,475 F B 25 51,770 G B 33 48,339 H C 1078,033 I C 25 35,602 J C 33 42,291

Coatings Preparation

Table II lists ingredients and their respective amounts used to producevarious exemplary coatings formulations prepared from the POLY(ALKYNYLCARBAMATE) PREPOLYMERS of Table 1. Formulation 0 in Table II wasprepared as follows. POLYOL A (3.105 g) and POLYISOCYANATE A (1.174 g)were added to a scintillation vial. The mixture was placed in a FLAKTECHmixer and mixed at 1800 rpm for 20-30 minutes until a homogenous mixturewas obtained. Meanwhile, smooth finish steel panels (Type QD, Q-LabCorporation) and polyethylene (PE) films were treated with acetonerinsing to remove surface contaminants. Formulation 0 was then drawndown onto the prepared panels and PE films using a 6 mil wet drawdownbar. The coatings were placed in a VWR Shel lab HF2 oven withpreprogrammed temperature setup for a consistent curing profile,described as follows: the solvent was allowed to flash at 30° C. for twohours, and the temperature was ramped to 100° C. at 1° C./min. Thecoatings were cured at 100° C. for four hours and cooled to 30° C.

TABLE II Amount FORMULATION Ingredient (g) 0 POLYISOCYANATE A 1.174POLYOL A 3.105 A POLY(ALKYNYL CARBAMATE) 1.582 PREPOLYMER A AZIDATEDPOLYOL A 3.079 n-BA 0.440 B POLY(ALKYNYL CARBAMATE) 1.155 PREPOLYMER BAZIDATED POLYOL A 1.998 n-BA 0.315 C POLY(ALKYNYL CARBAMATE) 1.305PREPOLYMER C AZIDATED POLYOL A 1.847 n-BA 0.315 D POLY(ALKYNYLCARBAMATE) 1.400 PREPOLYMER D AZIDATED POLYOL A 1.753 n-BA 0.315 EPOLY(ALKYNYL CARBAMATE) 1.166 PREPOLYMER E AZIDATED POLYOL A 1.985 n-BA0.315 F POLY(ALKYNYL CARBAMATE) 1.335 PREPOLYMER F AZIDATED POLYOL A1.818 n-BA 0.315 G POLY(ALKYNYL CARBAMATE) 1.439 PREPOLYMER G AZIDATEDPOLYOL A 1.715 n-BA 0.315 H POLY(ALKYNYL CARBAMATE) 1.174 PREPOLYMER HAZIDATED POLYOL A 1.979 n-BA 0.315 I POLY(ALKYNYL CARBAMATE) 1.353PREPOLYMER I AZIDATED POLYOL A 1.800 n-BA 0.315 J POLY(ALKYNYLCARBAMATE) 1.463 PREPOLYMER J AZIDATED POLYOL A 1.691 n-BA 0.315

FORMULATIONS A through J in Table II were prepared similarly toFORMULATION 0. As an example, FORMULATION A was prepared as follows:AZIDATED POLYOL A (3.079 g) and POLY(ALKYNYL CARBAMATE) PREPOLYMER A(1.582 g) were added to a scintillation vial. The mixture was dilutedwith n-BA (0.44 g), placed in a FLAKTECH mixer, and mixed at 1800 rpmfor 20-30 minutes until a homogenous mixture was obtained. Meanwhile,smooth-finish steel panels (Type QD, Q-Lab Corporation) and polyethylene(PE) films were treated with acetone rinsing to remove surfacecontaminants. FORMULATION A was then drawn down onto the prepared panelsand PE films using a 6 mil wet drawdown bar. The coatings were placed ina VWR Shel lab HF2 oven and subjected to the following pre-programmedcuring profile: the solvent was allowed to flash at 30° C. for twohours, and the temperature was ramped to 100° C. at 1° C./min. Thecoatings were cured at 100° C. for four hours and then cooled to 30° C.FORMULATIONS B through J were prepared similarly to FORMULATION A withingredients and amounts as provided in Table II.

Each coatings formulation was applied onto three smooth-finish steelpanels (Type QD, Q-Lab Corporation). Each coating test was conducted intriplicate (one replicate per panel). Coating tests were performed 12hours after the complete curing profile.

Reaction conversion/crosslink density was qualitatively compared via anMEK double rubs test up to 200 rubs using a 32 oz. (0.907 kg) hammercovered by four folds of cheesecloth according to ASTM D5402-15.

Hardness was measured via a pencil hardness test in accordance with ASTMD3363-05.

Table III lists coating performance properties of cured coatingsprepared from the formulations listed in Table II. FORMULATION 0 was apolyurethane control. FORMULATION A was an azido-alkyne control that hadno short chain mono alcohol substitution in the POLY(ALKYNYL CARBAMATE)PREPOLYMER A component. FORMULATIONS B through J were modifiedPOLY(ALKYNYL CARBAMATE) PREPOLYMERS that had 10, 25 or 33 mol %short-chain, mono alcohol modifications with GLYCOL ETHER A, GLYCOLETHER B, or GLYCOL ETHER C as reported in Table I. POLY(ALKYNYLCARBAMATE) PREPOLYMERS in FORMULATIONS B, C, and D had modificationsbased on GLYCOL ETHER A. POLY(ALKYNYL CARBAMATE) PREPOLYMERS inFORMULATIONS E, F, and G had modifications based on GLYCOL ETHER B.POLY(ALKYNYL CARBAMATE) PREPOLYMERS in FORMULATIONS H, I, and J hadmodifications based on GLYCOL ETHER C. All POLY(ALKYNYL CARBAMATE)PREPOLYMER modifications were accomplished by sacrificing alkynefunctionality. To the extent that isocyanate in the polyisocyanate wasconsumed with mono alcohol, less isocyanate was available in thepolyisocyanate for conversion to alkyne functional groups.

As can be appreciated by reference to Table III, sacrificingfunctionality to obtain lower viscosity POLY(ALKYNYL CARBAMATE)PREPOLYMERS, does not sacrifice coating performance. FORMULATIONS B, C,and D had GLYCOL ETHER A-modified POLY(ALKYNYL CARBAMATE) PREPOLYMERS(10, 25, and 33 mol % respectively), and coating performance was notsacrificed as can be seen by MEK double rubs. FORMULATIONS E, F, and Ghad GLYCOL ETHER B-modified POLY(ALKYNYL CARBAMATE) PREPOLYMERS (10, 25,and 33 mol % respectively), and coating performance was not sacrificedfor FORMULATIONS E and F and the performance decreased slightly forFORMULATION G, as can be seen by MEK double rubs. FORMULATIONS H, I, andJ had GLYCOL ETHER C-modified POLY(ALKYNYL CARBAMATE) PREPOLYMERS (10,25, and 33 mol % respectively), and coating performance was notsacrificed for FORMULATION H and the performance decreased slightly forFORMULATIONs I and J as can be seen by MEK double rubs.

TABLE III Pencil MEK T_(g) Formulation Hardness Double Rubs (DSC)(° C.)0 6H >200 46.95 A 8H >200 34.87 B 7H >200 26.30 C 6H >200 17.29 D5H >200 10.65 E 7H >200 24.65 F 3H >200 12.76 G  H 155 6.34 H 6H >20023.75 I 2H 180 11.85 J  B 135 4.04

This specification has been written with reference to variousnon-limiting and non-exhaustive embodiments. However, it will berecognized by persons having ordinary skill in the art that varioussubstitutions, modifications, or combinations of any of the disclosedembodiments (or portions thereof) may be made within the scope of thisspecification. Thus, it is contemplated and understood that thisspecification supports additional embodiments not expressly set forthherein. Such embodiments may be obtained, for example, by combining,modifying, or reorganizing any of the disclosed steps, components,elements, features, aspects, characteristics, limitations, and the like,of the various non-limiting embodiments described in this specification.In this manner, Applicant reserves the right to amend the claims duringprosecution to add features as variously described in thisspecification, and such amendments comply with the requirements of 35U.S.C. § 112(a), and 35 U.S.C. § 132(a).

Various aspects of the subject matter described herein are set out inthe following numbered clauses:

Clause 1. A poly(alkynyl carbamate) prepolymer comprising a reactionproduct of a polyisocyanate, an alkynol, and a glycol ether, whereinfrom 1 mol % to 33 mol % of isocyanate groups are reacted with glycolether and the remaining isocyanate groups are reacted with the alkynol.

Clause 2. The poly(alkynyl carbamate) prepolymer according to Clause 1,wherein the polyisocyanate is selected from the group consisting of1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate,2,2,4-trimethyl-1,6-hexamethylene diisocyanate, 1,12-dodecamethylenediisocyanate, cyclohexane-1,3-diisocyanate,cyclohexane-1,4-diisocyanate, 1-isocyanato-2-isocyanato-methylcyclopentane, 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethylcyclohexane (isophorone diisocyanate or IPDI),bis-(4-isocyanatocyclohexyl)methane,1,3-bis(isocyanatomethyl)-cyclohexane,1,4-bis(isocyanatomethyl)-cyclohexane,bis-(4-isocyanato-3-methyl-cyclohexyl)-methane,α,α,α′,α′-tetramethyl-1,3-xylene diisocyanate,α,α,α′,α′-tetramethy-1,4-xylene diisocyanate,1-isocyanato-1-methyl-4(3)-isocyanato-methyl cyclohexane,2,4-hexahydrotoluene diisocyanate, 2,6-hexahydrotoluene diisocyanate,toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), pentanediisocyanate (PDI)—bio-based), and, isomers of any of these; or mixturesof any of these.

Clause 3. The poly(alkynyl carbamate) prepolymer according to one ofClauses 1 and 2, wherein the polyisocyanate contains one or moreselected from the group consisting of isocyanurate, biuret, allophanate,uretdione, and iminooxadiazine dione groups.

Clause 4. The poly(alkynyl carbamate) prepolymer according to any one ofClauses 1 to 3, wherein the alkynol is selected from the groupconsisting of propargyl alcohol, 2-hydroxyethylpropiolate, and isomersof any of these; or mixtures of any of these.

Clause 5. The poly(alkynyl carbamate) prepolymer according to any one ofClauses 1 to 4, wherein the glycol ether is selected from the groupconsisting of ethylene glycol monomethyl ether, ethylene glycolmonoethyl ether, ethylene glycol monopropyl ether, ethylene glycolmonoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycolmonophenyl ether, ethylene glycol monobenzyl ether, propylene glycolmethyl ether, diethylene glycol monomethyl ether, diethylene glycolmonoethyl ether, diethylene glycol mono-n-butyl ether, anddipropyleneglycol methyl ether.

Clause 6. An alternative polyurethane composition comprising a reactionproduct of an azidated polyol and the poly(alkynyl carbamate) prepolymeraccording to any one of Clauses 1 to 5, wherein reaction occurs at atemperature of from 20° C. to 200° C., optionally in the presence of aCu^(I)-containing catalyst.

Clause 7. The alternative polyurethane composition according to Clause6, wherein the azidated polyol is a reaction product of a polyol and anazide anion.

Clause 8. The alternative polyurethane composition according to one ofClauses 6 and 7, wherein the azidated polyol is a reaction product of apolyol and methane sulfonyl chloride in presence of base, followed bydisplacement of methanesulfonate by an azide anion.

Clause 9. The alternative polyurethane composition according to one ofClauses 7 and 8, wherein the polyol is selected from the groupconsisting of polyalkylene ether polyols, polyester polyols, hydroxylcontaining polycaprolactones, hydroxyl-containing (meth)acrylicpolymers, polycarbonate polyols, polyurethane polyols and combinationsthereof.

Clause 10. The alternative polyurethane composition according to Clauses6 to 9, wherein the Cu^(I)-containing catalyst comprises a Cu^(II)catalyst and a reducing agent.

Clause 11. The alternative polyurethane composition according to Clause10, wherein the Cu^(II) catalyst is selected from the group consistingof copper(II) chloride, CuCl₂[PMDETA], copper(II) bromide, copper(II)iodide, copper(II) sulfate, and copper(II) acetate monohydrate.

Clause 12. The alternative polyurethane composition according to one ofClauses 10 and 11, wherein the reducing agent is selected from the groupconsisting of triphenyl phosphine, sodium ascorbate, tin(II)2-ethylhexanoate, and hydroquinone.

Clause 13. One of a coating, an adhesive, a sealant, a film, anelastomer, a casting, a foam, and a composite comprising the alternativepolyurethane composition according to any one of Clauses 6 to 12.

Clause 14. A substrate having applied thereto the one of a coating, anadhesive, a sealant, a film, an elastomer, a casting, a foam, and acomposite according to Clause 13.

Clause 15. A process of producing a poly(alkynyl carbamate) prepolymer,the process comprising reacting a polyisocyanate, an alkynol, and aglycol ether, wherein from 1 mol % to 33 mol % of isocyanate groups arereacted with glycol ether and the remaining isocyanate groups arereacted with the alkynol.

Clause 16. The process according to Clause 15, wherein thepolyisocyanate is selected from the group consisting of1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate,2,2,4-trimethyl-1,6-hexamethylene diisocyanate, 1,12-dodecamethylenediisocyanate, cyclohexane-1,3-diisocyanate,cyclohexane-1,4-diisocyanate, 1-isocyanato-2-isocyanato-methylcyclopentane, 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethylcyclohexane (isophorone diisocyanate or IPDI),bis-(4-isocyanatocyclohexyl)methane,1,3-bis(isocyanatomethyl)-cyclohexane,1,4-bis(isocyanatomethyl)-cyclohexane,bis-(4-isocyanato-3-methyl-cyclohexyl)-methane,α,α,α′,α′-tetramethyl-1,3-xylene diisocyanate,α,α,α′,α′-tetramethy-1,4-xylene diisocyanate,1-isocyanato-1-methyl-4(3)-isocyanato-methyl cyclohexane,2,4-hexahydrotoluene diisocyanate, 2,6-hexahydrotoluene diisocyanate,toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), pentanediisocyanate (PDI)—bio-based), and, isomers of any of these; or mixturesof any of these.

Clause 17. The process according to one of Clauses 15 and 16, whereinthe polyisocyanate contains one or more selected from the groupconsisting of isocyanurate, biuret, allophanate, uretdione, andiminooxadiazine dione groups.

Clause 18. The process according to any one of Clauses 15 to 17, whereinthe alkynol is selected from the group consisting of propargyl alcohol,2-hydroxyethylpropiolate, and isomers of any of these; or mixtures ofany of these.

Clause 19. The process according to any one of Clauses 15 to 18, whereinthe glycol ether is selected from the group consisting of ethyleneglycol monomethyl ether, ethylene glycol monoethyl ether, ethyleneglycol monopropyl ether, ethylene glycol monoisopropyl ether, ethyleneglycol monobutyl ether, ethylene glycol monophenyl ether, ethyleneglycol monobenzyl ether, propylene glycol methyl ether, diethyleneglycol monomethyl ether, diethylene glycol monoethyl ether, diethyleneglycol mono-n-butyl ether, and dipropyleneglycol methyl ether.

Clause 20. A process of making an alternative polyurethane composition,the process comprising reacting an azidated polyol and the poly(alkynylcarbamate) prepolymer according to any one of Clauses 15 to 19 at atemperature of from 20° C. to 200° C., optionally in the presence of aCu^(I)-containing catalyst.

Clause 21. The process according to Clause 20, wherein the azidatedpolyol is a reaction product of a polyol and an azide anion.

Clause 22. The process according to one of Clauses 20 and 21, whereinthe azidated polyol is a reaction product of a polyol and methanesulfonyl chloride in presence of base, followed by displacement ofmethanesulfonate by an azide anion.

Clause 23. The process according to one of Clauses 21 and 22, whereinthe polyol is selected from the group consisting of polyalkylene etherpolyols, polyester polyols, hydroxyl containing polycaprolactones,hydroxyl-containing (meth)acrylic polymers, polycarbonate polyols,polyurethane polyols and combinations thereof.

Clause 24. The process according to Clauses 20 to 23, wherein theCu^(I)-containing catalyst comprises a Cu^(II) catalyst and a reducingagent.

Clause 25. The process according to Clause 24, wherein the Cu^(II)catalyst is selected from the group consisting of copper(II) chloride,CuCl₂[PMDETA], copper(II) bromide, copper(II) iodide, copper(II)sulfate, copper (II) 2-ethylhexanoate, and copper (II) acetatemonohydrate.

Clause 26. The process according to Clause 24, wherein the reducingagent is selected from the group consisting of triphenyl phosphine,sodium ascorbate, tin(II) 2-ethylhexanoate, and hydroquinone.

Clause 27. One of a coating, an adhesive, a sealant, a film, anelastomer, a casting, a foam, and a composite comprising the alternativepolyurethane composition made according to the process of any one ofClauses 20 to 26.

Clause 28. A substrate having applied thereto the one of a coating, anadhesive, a sealant, a film, an elastomer, a casting, a foam, and acomposite according to Clause 27.

What is claimed is:
 1. A poly(alkynyl carbamate) prepolymer comprising areaction product of: a polyisocyanate; an alkynol; and a glycol ether,wherein from 1 mol % to 33 mol % of isocyanate groups are reacted withglycol ether and the remaining isocyanate groups are reacted with thealkynol.
 2. The poly(alkynyl carbamate) prepolymer according to claim 1,wherein the polyisocyanate is selected from the group consisting of1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate,2,2,4-trimethyl-1,6-hexamethylene diisocyanate, 1,12-dodecamethylenediisocyanate, cyclohexane-1,3-diisocyanate,cyclohexane-1,4-diisocyanate, 1-isocyanato-2-isocyanato-methylcyclopentane, 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethylcyclohexane (isophorone diisocyanate or IPDI),bis-(4-isocyanatocyclohexyl)methane,1,3-bis(isocyanatomethyl)-cyclohexane,1,4-bis(isocyanatomethyl)-cyclohexane,bis-(4-isocyanato-3-methyl-cyclohexyl)-methane,α,α,α′,α′-tetramethyl-1,3-xylene diisocyanate,α,α,α′,α′-tetramethy-1,4-xylene diisocyanate,1-isocyanato-1-methyl-4(3)-isocyanato-methyl cyclohexane,2,4-hexahydrotoluene diisocyanate, 2,6-hexahydrotoluene diisocyanate,toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), pentanediisocyanate (PDI)—bio-based), and, isomers of any of these; or mixturesof any of these.
 3. The poly(alkynyl carbamate) prepolymer according toclaim 1, wherein the polyisocyanate contains one or more selected fromthe group consisting of isocyanurate, biuret, allophanate, uretdione,and iminooxadiazine dione groups.
 4. The poly(alkynyl carbamate)prepolymer according to claim 1, wherein the alkynol is selected fromthe group consisting of propargyl alcohol, 2-hydroxyethylpropiolate, andisomers of any of these; or mixtures of any of these.
 5. Thepoly(alkynyl carbamate) prepolymer according to claim 1, wherein theglycol ether is selected from the group consisting of ethylene glycolmonomethyl ether, ethylene glycol monoethyl ether, ethylene glycolmonopropyl ether, ethylene glycol monoisopropyl ether, ethylene glycolmonobutyl ether, ethylene glycol monophenyl ether, ethylene glycolmonobenzyl ether, propylene glycol methyl ether, diethylene glycolmonomethyl ether, diethylene glycol monoethyl ether, diethylene glycolmono-n-butyl ether, and dipropyleneglycol methyl ether.
 6. Analternative polyurethane composition comprising a reaction product of:an azidated polyol: and the poly(alkynyl carbamate) prepolymer accordingto claim 1, wherein reaction occurs at a temperature of from 20° C. to200° C., optionally in the presence of a Cu^(I)-containing catalyst. 7.The alternative polyurethane composition according to claim 6, whereinthe azidated polyol is a reaction product of a polyol and an azideanion.
 8. The alternative polyurethane composition according to claim 7,wherein the polyol is selected from the group consisting of polyalkyleneether polyols, polyester polyols, hydroxyl containing polycaprolactones,hydroxyl-containing (meth)acrylic polymers, polycarbonate polyols,polyurethane polyols and combinations thereof.
 9. The alternativepolyurethane composition according to claim 6, wherein theCu^(I)-containing catalyst comprises a Cu^(II) catalyst and a reducingagent.
 10. The alternative polyurethane composition according to claim9, wherein the Cu^(II) catalyst is selected from the group consisting ofcopper(II) chloride, CuCl₂[PMDETA], copper(II) bromide, copper(II)iodide, copper(II) sulfate, copper(II) 2-ethylhexanoate, and copper (II)acetate monohydrate.
 11. The alternative polyurethane compositionaccording to claim 9, wherein the reducing agent is selected from thegroup consisting of triphenyl phosphine, sodium ascorbate, tin(II)2-ethylhexanoate, and hydroquinone.
 12. One of a coating, an adhesive, asealant, a film, an elastomer, a casting, a foam, and a compositecomprising the alternative polyurethane composition according to claim6.
 13. A substrate having applied thereto the one of a coating, anadhesive, a sealant, a film, an elastomer, a casting, a foam, and acomposite according to claim
 12. 14. A process of producing apoly(alkynyl carbamate) prepolymer, the process comprising reacting: apolyisocyanate: an alkynol: and of a glycol ether, wherein from 1 mol %to 33 mol % of isocyanate groups are reacted with glycol ether and theremaining isocyanate groups are reacted with the alkynol.
 15. Theprocess according to claim 14, wherein the polyisocyanate is selectedfrom the group consisting of 1,4-tetramethylene diisocyanate,1,6-hexamethylene diisocyanate, 2,2,4-trimethyl-1,6-hexamethylenediisocyanate, 1,12-dodecamethylene diisocyanate,cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate,1-isocyanato-2-isocyanato-methyl cyclopentane,1-isocyanato-3-isocyanatomethyl-3,5,5-trimethyl cyclohexane (isophoronediisocyanate or IPDI), bis-(4-isocyanatocyclohexyl)methane,1,3-bis(isocyanatomethyl)-cyclohexane,1,4-bis(isocyanatomethyl)-cyclohexane,bis-(4-isocyanato-3-methyl-cyclohexyl)-methane,α,α,α′,α′-tetramethyl-1,3-xylene diisocyanate,α,α,α′,α′-tetramethy-1,4-xylene diisocyanate,1-isocyanato-1-methyl-4(3)-isocyanato-methyl cyclohexane,2,4-hexahydrotoluene diisocyanate, 2,6-hexahydrotoluene diisocyanate,toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), pentanediisocyanate (PDI)—bio-based), and, isomers of any of these; or mixturesof any of these.
 16. The process according to claim 14, wherein thepolyisocyanate contains one or more selected from the group consistingof isocyanurate, biuret, allophanate, uretdione, and iminooxadiazinedione groups.
 17. The process according to claim 14, wherein the alkynolis selected from the group consisting of propargyl alcohol,2-hydroxyethylpropiolate, and isomers of any of these; or mixtures ofany of these.
 18. The process according to claim 14, wherein the glycolether is selected from the group consisting of ethylene glycolmonomethyl ether, ethylene glycol monoethyl ether, ethylene glycolmonopropyl ether, ethylene glycol monoisopropyl ether, ethylene glycolmonobutyl ether, ethylene glycol monophenyl ether, ethylene glycolmonobenzyl ether, propylene glycol methyl ether, diethylene glycolmonomethyl ether, diethylene glycol monoethyl ether, diethylene glycolmono-n-butyl ether, and dipropyleneglycol methyl ether.
 19. A process ofproducing an alternative polyurethane composition, the processcomprising reacting: an azidated polyol; and the poly(alkynyl carbamate)prepolymer according to claim 14 at a temperature of from 20° C. to 200°C., optionally in the presence of a Cu^(I)-containing catalyst.
 20. Theprocess according to claim 19, wherein the azidated polyol is a reactionproduct of a polyol and an azide anion.
 21. The process according toclaim 19, wherein the polyol is selected from the group consisting ofpolyalkylene ether polyols, polyester polyols, hydroxyl containingpolycaprolactones, hydroxyl-containing (meth)acrylic polymers,polycarbonate polyols, polyurethane polyols and combinations thereof.22. The process according to claim 19, wherein the Cu^(I)-containingcatalyst comprises a Cu^(II) catalyst and a reducing agent.
 23. Theprocess according to claim 22, wherein the Cu^(II) catalyst is selectedfrom the group consisting of copper(II) chloride, CuCl₂[PMDETA],copper(II) bromide, copper(II) iodide, copper(II) sulfate, copper(II)2-ethylhexanoate, and copper(II) acetate monohydrate.
 24. The processaccording to claim 22, wherein the reducing agent is selected from thegroup consisting of triphenyl phosphine, sodium ascorbate, tin(II)2-ethylhexanoate, and hydroquinone.
 25. One of a coating, an adhesive, asealant, a film, an elastomer, a casting, a foam, and a compositecomprising the alternative polyurethane composition made according tothe process of claim
 19. 26. A substrate having applied thereto the oneof a coating, an adhesive, a sealant, a film, an elastomer, a casting, afoam, and a composite according to claim 25.